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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,135 records · Page 63
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Alternate propellants for the space shuttle solid rocket booster motors

As part of the Shuttle Exhaust Effects Panel (SEEP) program for fiscal year 1973, a limited study was performed to determine the feasibility of minimizing the environmental impact associated with the operation of the solid rocket booster motors (SRBMs) in projected space shuttle launches. Eleven hypothetical and two existing limited-experience propellants were evaluated as possible alternates to a well-proven state-of-the-art reference propellant with respect to reducing emissions of primary concern: namely, hydrogen chloride (HCl) and aluminum oxide (Al2O3). The study showed that it would be possible to develop a new propellant to effect a considerable reduction of HCl or Al2O3 emissions. At the one extreme, a 23% reduction of HCl is possible along with a ll% reduction in Al2O3, whereas, at the other extreme, a 75% reduction of Al2O3 is possible, but with a resultant 5% increase in HCl.

Source record↗
NASA NTRS1973

NASTRAN buckling study of a linear induction motor reaction rail

NASTRAN was used to study problems associated with the installation of a linear induction motor reaction rail test track. Specific problems studied include determination of the critical axial compressive buckling stress and establishment of the lateral stiffness of the reaction rail under combined loads. NASTRAN results were compared with experimentally obtained values and satisfactory agreement was obtained. The reaction rail was found to buckle at an axial compressive stress of 11,400 pounds per square inch. The results of this investigation were used to select procedures for installation of the reaction rail.

Williams, J. G.↗
NASA NTRS1973

Some environmental considerations relating to the interaction of the solid rocket motor exhaust with the atmosphere: Predicted chemical composition of exhaust species and predicted conditions for the formation of HCl aerosol

The exhaust products of a solid rocket motor using as propellant 14% binder, 16% aluminum, and 70% (wt) ammonium perchlorate consist of hydrogen chloride, water, alumina, and other compounds. The equilibrium and some frozen compositions of the chemical species upon interaction with the atmosphere were computed. The conditions under which hydrogen chloride interacts with the water vapor in humid air to form an aerosol containing hydrochloric acid were computed for various weight ratios of air/exhaust products. These computations were also performed for the case of a combined SRM and hydrogen-oxygen rocket engine. Regimes of temperature and relative humidity where this aerosol is expected were identified. Within these regimes, the concentration of HCL in the aerosol and weight fraction of aerosol to gas phase were plotted. Hydrochloric acid aerosol formation was found to be particularly likely in cool humid weather.

Rhein, R. A.↗
NASA NTRS1974

Development and demonstration of flueric sounding rocket motor ignition

An analytical and experimental program is described which established a flueric rocket motor ignition system concept incorporating a pneumatic match with a simple hand pump as the only energy source. An evaluation was made of this concept to determine the margins of the operating range and capabilities of every component of the system. This evaluation included a determination of power supply requirements, ignitor geometry and alinement, ignitor/propellant interfacing and materials and the effects of ambient temperatures and pressure. It was demonstrated that an operator using a simple hand pump for 30 seconds could ignite BKNO3 at a standoff distance of 100 m (330 ft) with the only connection to the ignitor being a piece of plastic pneumatic tubing.

Marchese, V. P.↗
NASA NTRS1973

Solid motor aft closure insulation erosion

The erosion rate of aft closure insulation in a number of large solid propellant motors was empirically analyzed by correlating the average ablation rate with a number of variables that had previously been demonstrated to affect heat flux. The main correlating parameter was a heat flux based on the simplified Bartz heat transfer coefficient corrected for two-dimensional effects. A multiplying group contained terms related to port-to-throat ratio, local wall angle, grain geometry and nozzle cant angle. The resulting equation gave a good correlation and is a useful design tool.

Stampfl, E.↗
NASA NTRS1973

A centre for accommodative vergence motor control

Latencies in accommodation, accommodative-vergence, and pupil-diameter responses to changing accommodation stimuli, as well as latencies in pupil response to light-intensity changes were measured. From the information obtained, a block diagram has been derived that uses the least number of blocks for representing the accommodation, accommodative-vergence, and pupil systems. The signal transmission delays over the various circuits of the model have been determined and compared to known experimental physiological-delay data. The results suggest the existence of a motor center that controls the accommodative vergence and is completely independent of the accommodation system.

Wilson, D.↗
NASA NTRS1974

Computer-assisted design in perceptual-motor skills research

A categorization was made of independent variables previously found to be potent in simple perceptual-motor tasks. A computer was then used to generate hypothetical factorial designs. These were evaluated in terms of literature trends and pragmatic criteria. Potential side-effects of machine-assisted research strategy were discussed.

Rogers, C. A., Jr.↗
NASA NTRS1973

Modeling and measuring limb fine-motor unsteadiness

Fine-motor unsteadiness its properties, conceptual and analytical models, and experimental measurements is examined. Based on a data review, the tentative model derived includes: neuromuscular system, grip interface, and control system dynamic elements. The properties of this model change with muscle tension and match a wide group of extant data. A simple experiment was performed to investigate the amplitude/force relationships of the tremor mode. As the finger-pull force increased from 5 to 20 Newtons, the tremor mode frequency for a given individual stayed within roughly + or - 1 Hz over a range from 9-12 Hz, while the average magnitude of the rms tremor acceleration increased tenfold. A standardized test for making such measurements is given and applications in the fields of psychophysiological stress and strain measurements are mentioned.

Magdaleno, R. E.↗
NASA NTRS1975

Phase 2 study of improved materials for use on Scout rocket motor nozzles

Nozzle material performance data were obtained, and the feasibility was determined of using new materials on the Scout rocket motor nozzles. Stress and heat transfer analyses were conducted to aid in the selection of optimum materials for nozzle tests. A reimpregnated and graphitized throat insert was fabricated along with two nozzles with ablative throats. The dissection and determining of char and erosion of two nozzles fired on X-259 loaded cases are discussed; one of the nozzles used a graphite phenolic ablative throat insert, and the other unit was a standard X-259 nozzle with a reduced area ATJ graphite throat insert.

Stutzman, R. D.↗
NASA NTRS1975

Thrust vector control for the Space Shuttle Solid Rocket Motor

Thrust vector control (TVC) for the Space Shuttle Solid Rocket Motor (SRM) is obtained by omniaxis vectoring of the nozzle. The development and integration of the system are under the cognizance of Marshall Space Flight Center (MSFC). The nozzle and flexible bearing have been designed and will be built by Thiokol Corporation/Wasatch Division. The vector requirements of the system, the impact of multiple reuse on the components, and the unique problems associated with a large flexible bearing are discussed. The design details of each of the major TVC subcomponents are delineated. The subscale bearing development program and the overall development schedule also are presented.

Counter, D. N.↗
NASA NTRS1977

Ironless-armature brushless motor

Device uses 12-pole samarium cobalt permanent-magnet rotor and three Hall-effect sensors for commutation. In prototype motor, torque constant (3-phase delta) is 65 oz-in/amp; electrical time constant (L/R) is 0.2 x 0.001 sec, and armature resistance is 20 ohms.

Fisher, R. L.↗
NASA NTRS1975

NO sub X Deposited in the Stratosphere by the Space Shuttle Solid Rocket Motors

The possible effects of the interaction of the plumes from the two solid rocket motors (SRM) from the space shuttles and mixing of the rocket exhaust products and ambient air in the base recirculation region on the total nitrous oxide deposition rate in the stratosphere were investigated. It was shown that these phenomena will not influence the total NOx deposition rate. It was also shown that uncertainties in the particle size of Al2O3, size distributions and particle/gas drag and heat transfer coefficients will not have a significant effect on the predicted NOx deposition rate. The final results show that the total mass flow of NOx leaving the plume at 30 km altitude is 4000 g./sec with a possible error factor of 3. For a vehicle velocity of 1140 meter/sec this yields an NOx deposition rate of about 3.5 g./meter. The corresponding HCl deposition rate at this altitude is about a factor of 500 greater than this value.

Pergament, H. S.↗
NASA NTRS1976

The production of nitric oxide in the troposphere as a result of solid-rocket-motor afterburning

As part of an ongoing assessment of the environmental effects of solid-rocket-motor operations in the troposphere, estimates were made of the nitric oxide produced in the troposphere by the space shuttle and Titan 3-C boosters. Calculations were made with the low-altitude plume computer program and included the effects of coupled finite-rate chemistry and turbulent mixing. A recent measurement of nitric oxide taken in the effluent cloud of a Titan 3-C booster is compared with calculations made with this computer code. The various chemical reactions of the exhaust gases are listed in tabular form.

Stewart, R. B.↗
NASA NTRS1975

Solid-propellant rocket motor ballistic performance variation analyses

Results are presented of research aimed at improving the assessment of off-nominal internal ballistic performance including tailoff and thrust imbalance of two large solid-rocket motors (SRMs) firing in parallel. Previous analyses using the Monte Carlo technique were refined to permit evaluation of the effects of radial and circumferential propellant temperature gradients. Sample evaluations of the effect of the temperature gradients are presented. A separate theoretical investigation of the effect of strain rate on the burning rate of propellant indicates that the thermoelastic coupling may cause substantial variations in burning rate during highly transient operating conditions. The Monte Carlo approach was also modified to permit the effects on performance of variation in the characteristics between lots of propellants and other materials to be evaluated. This permits the variabilities for the total SRM population to be determined. A sample case shows, however, that the effect of these between-lot variations on thrust imbalances within pairs of SRMs is minor in compariosn to the effect of the within-lot variations. The revised Monte Carlo and design analysis computer programs along with instructions including format requirements for preparation of input data and illustrative examples are presented.

Sforzini, R. H.↗
NASA NTRS1976

SRM attrition rate study of the aft motor case segments due to water impact cavity collapse loading

The attrition assessment of the aft segments of Solid Rocket Motor due to water impact requires the establishment of a correlation between loading occurrences and structural capability. Each discrete load case, as identified by the water impact velocities and angle, varies longitudinally and radially in magnitude and distribution of the external pressure. The distributions are further required to be shifted forward or aft one-fourth the vehicle diameter to assure minimization of the effect of test instrumentation location for the load determinations. The asymmetrical load distributions result in large geometric nonlinearities in structural response. The critical structural response is progressive buckling of the case. Discrete stiffeners have been added to these aft segments to aid in gaining maximum structural capability for minimum weight addition for resisting these loads. This report presents the development of the attrition assessment of the aft segments and includes the rationale for eliminating all assessable conservatisms from this assessment.

Crockett, C. D.↗
NASA NTRS1976

The JPL advanced propulsion module motor chamber

A Kevlar 49/epoxy chamber has been developed for the advanced propulsion module motor. This chamber was successfully designed, fabricated, and hydroproof-tested at 511.6 N/sq cm. The fabrication, interior dimensional inspection, and proof test are discussed, showing that the chamber will be capable of achieving the design burst pressure of 639.8 N/sq cm. The projected chamber growth at 448.2 N/sq cm is presented based on the strain gage and volumetric growth data collected in that proof test.

Jensen, W. M.↗